Is lesson me hum seekhenge:
- Function (Method) kya hai
- Parameterized Functions
- Return Type Functions
- Java me functions ka syntax
- Practice Challenges:
- Armstrong Number
- Digit Sum
- Factorials
- Fibonacci Series
- Greatest of numbers
- LCM / GCD
- Odd Numbers
- Palindrome
- Prime Numbers
- Table Print
- Return Opposite / Reverse Number
Function ya Method ek block of code hai jo reusable hota hai aur specific task perform karta hai.
- Function ek program ko modular bana deta hai
- Ek baar function define karke multiple times use kiya ja sakta hai
- Function program ko readable aur maintainable banata hai
returnType functionName(parameters){
// code
return value; // optional, if returnType is void then return not required
}Explanation:
| Part | Meaning |
|---|---|
| returnType | function ka type ya void |
| functionName | function ka naam |
| parameters | input arguments (optional) |
| return | value return karne ke liye (optional) |
public class SimpleFunction {
static void greet(){
System.out.println("Hello, Sujit!");
}
public static void main(String[] args) {
greet(); // function call
}
}Output:
Hello, Sujit!
Function parameters accept kar sakta hai.
public class ParameterFunction {
static void greet(String name){
System.out.println("Hello, " + name + "!");
}
public static void main(String[] args) {
greet("Sujit"); // passing parameter
}
}Output:
Hello, Sujit!
Function kuch value return kar sakta hai.
public class ReturnFunction {
static int add(int a, int b){
return a + b;
}
public static void main(String[] args) {
int result = add(5, 7);
System.out.println(result);
}
}Output:
12
Ye practice challenges aapko logic building aur function usage me help karenge.
public class Armstrong {
static boolean isArmstrong(int num){
int sum = 0, temp = num;
while(temp != 0){
int rem = temp % 10;
sum += rem * rem * rem;
temp /= 10;
}
return sum == num;
}
public static void main(String[] args) {
int number = 153;
System.out.println(isArmstrong(number));
}
}public class DigitSum {
static int sumDigits(int num){
int sum = 0;
while(num != 0){
sum += num % 10;
num /= 10;
}
return sum;
}
public static void main(String[] args) {
System.out.println(sumDigits(1234)); // 10
}
}public class Factorial {
static int factorial(int n){
int fact = 1;
for(int i=1;i<=n;i++){
fact *= i;
}
return fact;
}
public static void main(String[] args) {
System.out.println(factorial(5)); // 120
}
}public class Fibonacci {
static void fibonacci(int n){
int a=0, b=1;
System.out.print(a + " " + b + " ");
for(int i=3; i<=n; i++){
int c = a + b;
System.out.print(c + " ");
a = b;
b = c;
}
}
public static void main(String[] args) {
fibonacci(7);
}
}Output:
0 1 1 2 3 5 8
public class Greatest {
static int max(int a, int b){
return (a > b) ? a : b;
}
public static void main(String[] args) {
System.out.println(max(10, 20));
}
}public class LCMGCD {
static int gcd(int a, int b){
while(b != 0){
int temp = b;
b = a % b;
a = temp;
}
return a;
}
static int lcm(int a, int b){
return (a * b) / gcd(a, b);
}
public static void main(String[] args) {
System.out.println(gcd(12,18)); // 6
System.out.println(lcm(12,18)); // 36
}
}public class OddNumbers {
static void printOdd(int n){
for(int i=1; i<=n; i+=2){
System.out.print(i + " ");
}
}
public static void main(String[] args) {
printOdd(10); // 1 3 5 7 9
}
}public class Palindrome {
static boolean isPalindrome(int num){
int rev=0, temp=num;
while(temp != 0){
rev = rev*10 + temp%10;
temp /= 10;
}
return rev == num;
}
public static void main(String[] args) {
System.out.println(isPalindrome(121)); // true
}
}public class PrimeCheck {
static boolean isPrime(int n){
if(n<=1) return false;
for(int i=2;i<=Math.sqrt(n);i++){
if(n%i == 0) return false;
}
return true;
}
public static void main(String[] args) {
System.out.println(isPrime(13)); // true
}
}public class TablePrint {
static void printTable(int n){
for(int i=1;i<=10;i++){
System.out.println(n + " x " + i + " = " + (n*i));
}
}
public static void main(String[] args) {
printTable(5);
}
}public class ReverseNumber {
static int reverseNum(int num){
int rev=0;
while(num != 0){
rev = rev*10 + num%10;
num /= 10;
}
return rev;
}
public static void main(String[] args) {
System.out.println(reverseNum(1234)); // 4321
}
}- Functions code ko modular aur reusable banate hain
- Parameterized functions input lete hain
- Return type functions output dete hain
- Functions practice challenges ke liye best hain
1️⃣ Function kya hai?
2️⃣ Java me parameterized function kaise banate hain?
3️⃣ Return type function ka use kya hai?
4️⃣ Armstrong number ka logic kya hota hai?
5️⃣ Fibonacci series function me kaise implement karte hain?
Is lesson me humne seekha:
✔ Function / Method
✔ Parameter Function
✔ Return Function
✔ Practice challenges – Armstrong, DigitSum, Factorial, Fibonacci, Greatest, LCM/GCD, Odd, Palindrome, Prime, Table Print, Reverse
Functions Java programming me code ko clean aur reusable banane ke liye bahut important hain.
Next lesson me hum seekhenge:
- Arrays in Java
- Single dimension array
- Multi dimension array
- Array traversal & operations